A Text Book on Engineering Graphics - Central Board of Secondary ...

ISOMETRIC PROJECTION
Steps:
1. Draw an isometric projection of the box that encloses hexagonal prism having
two faces parallel to V.P.
2. Indicate the centre of the top hexagon face with conventional lines.
3. Around the centre 'O' draw the equilateral triangle base of the pyramid. Raise the
axis of the pyramid from the center to apex.
4. Join all the visible edges (no hidden lines) of the two solids by using thick lines.
5. Complete the isometric projection of the two solids with dimensioning, direction
of viewing and their common axis using conventional lines.
Example: 1.25
Draw an Isometric Projection of a vertical regular pentagonal pyramid resting
centrally, having one base edge away from the observer parallel to V.P., on top of
a vertical cylinder. Side of the pentagon = 32 mm, height of pyramid = 50 mm,
diameter of cylinder = 76 mm and height of cylinder = 40 mm.
HELPING FIGURE
32
O
ENGINEERING GRAPHICS
F
Ø76
Fig 1.32
o
30
O
50
ISOMETRIC PROJECTION
30
o
40
29